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Biomedical subjects

R Okamura

Publications and source records attributed to R Okamura.

At least 73 records · Page 4Linked to original sources
PubMed1985

The serratial 56K protease as a major pathogenic factor in serratial keratitis. Clinical and experimental study.

A possible cause and the difference in clinical severity of serratial keratitis were investigated. Two strains of Serratia marcescens were isolated: one from a patient with severe liquefactive keratitis, who had diabetes mellitus, and one from a patient with mild superficial keratitis, but who had no underlying disease. When the same numbers of bacteria were injected separately into corneas of the same rabbits or guinea pigs, the strain from the first patient elicited severe corneal destruction, remarkable intracorneal edema; and liquefactive necrosis, but the strain from the second caused mild keratitis with erosion or intracorneal abscess. The keratitis induced by the former strain required a longer time to heal, and the prognosis was poorer than that for the other keratitis. Therefore, the difference in severity between the two cases of experimentally induced keratitis paralleled that of the clinical cases. Thus, the severity of the serratial keratitis might be attributed more to the virulence of the bacteria than the condition of the host. The virulence factor seemed to be a heat-labile metabolic product (or products) of the bacteria. To clarify this virulence factor, the major secretory protease (56K protease) produced by these two strains of bacteria was compared by using in vitro and in vivo systems. The virulent strain produced about ten times more protease during culture than the less virulent strain. When injected into the corneas of experimental animals, the 56K protease from the virulent strain induced severe lesions similar to those caused by the living virulent strain of bacteria. These results indicated that one of the major factors causing the virulence was correlated with the tissue destructive 56K protease produced by S. marcescens.

Aged↗
PubMed1985

[By-pass surgery with infusion therapy for non-resectable esophageal cancer].

In principle, the following three steps are considered for by-pass surgery; I. A gastric tube is moved up to the retro-sternal or to the ante-thoracic position. A T-tube is the inserted in the mid position of the gastric tube for decompression and drainage. 2. A retention vinyl tube is inserted in to the excluded esophagus for the purpose of post infusion therapy and for evaluation of the therapy. 3. A Roux-Y anastomotic internal fistula is placed at the distal site of the excluded esophagus. As a plan for combined therapy, PANa-Oil bleomycin (oil bleomycin 30 mg, PANa 0.5 g) is the infused into the isolated esophagus after the by-pass operation and the clinical effect is evaluated by introducing a radiopaque medium into the excluded esophagus via an inserted vinyl tube. Such infusion therapy after by-pass surgery was given to 3 patients and in 1 patient it was very effective. This suggested a positive effect on survival in cases of non-resectable esophageal cancer without side effects.

Acrylic Resins↗
PubMed1985

Studies of human tear proteins: 4. Analysis by crossed immunoelectrophoresis of tears in various diseases.

Tears were collected from patients with familial amyloidotic polyneuropathy (FAP), orbital tumors, sarcoidosis, trigeminal and facial nerve palsy and corneal ulcer. These tears were analyzed by crossed immunoelectrophoresis. Two cases of FAP with deficiency of lacrimation and keratoconjunctivitis sicca showed normal tear protein patterns. In these cases, the deficiency of lacrimation may have been due chiefly to disturbance of the peripheral parasympathetic nerve innervating the lacrimal gland. Five other patients with FAP showed from slight to severe decrease in the tear-specific proteins. One of two cases with lacrimal gland tumor showed a decrease in the tear-specific proteins before removal of the tumor. After the surgery two patients showed significant decrease or disappearance of the tear-specific proteins. Three cases with other orbital tumors revealed no alterations in production of tear proteins. The case of sarcoidosis with keratoconjunctivitis sicca showed a decrease in the tear-specific proteins. Lacrimal gland involvement in sarcoidosis was confirmed by the tear protein analysis. The patient with facial and trigeminal nerve palsy showed a decrease in the tear-specific proteins. This was thought to be due to atrophy of the main lacrimal gland caused by functional disturbance of the lacrimal nerve. The analysis of tear proteins is useful in the diagnosis of lacrimal gland tumor disturbing the gland function and also of other diseases involving the lacrimal gland.

Adult↗
PubMed1984

Role of the zinc atom in the activity and conformational stability of serratial 56K protease. A fluorometric study.

We found a zinc content of 1 atom per mol in 56K protease (produced by the gram-negative bacterium Serratia marcescens kums 3958) by the neutron activation method. Selective removal of the functional zinc ion from 56K protease with 10 mM tetraethylenepentamine (TEP) in the presence of 10 mM CaCl2 at room temperature at pH 8.0 resulted in complete loss of the enzyme activity without affecting the lambda max of the enzyme, but with a 10% decrease in fluorescence intensity. Ethylenediaminetetraacetic acid (EDTA) at 10 mM gave similar results at pH 5.0, but produced a 30% decrease in fluorescence intensity. Melting profile experiments carried out by monitoring the fluorescence intensity at 333 nm showed a melting temperature (Tm) of about 61.0, 62.5, and 60.0 degrees C at pH 5.0, 7.0, and 8.0, respectively. Tm became much lower upon removal of the zinc ion, falling to 42.5 degrees C with 10 mM TEP or to 47.5 degrees C with 10 mM EDTA in the presence of 10 mM CaCl2. The CD data showed very little change in conformation upon removal of the zinc ion under physiological conditions, but the conformation appears to be readily disrupted to a denatured form by changing either temperature or pH or by exposure to denaturants. These results suggest that a single zinc ion is essential for the enzyme function and contributes to the conformational integrity of the enzyme, but tryptophan residues appear to be not directly related to the enzyme activity.

Circular Dichroism↗
PubMed1984

Purification and characterization of four proteases from a clinical isolate of Serratia marcescens kums 3958.

Four distinct proteases were purified to homogeneity from culture filtrates of Serratia marcescens kums 3958, a fresh isolate from a patient with a severe corneal ulcer. Purification was achieved by ammonium sulfate precipitation, DEAE-cellulose ion-exchange chromatography, and Sephadex gel filtration chromatography. The proteases were differentiated from each other by polyacrylamide gel electrophoresis with or without sodium dodecyl sulfate and by immunodiffusion in agarose gels. The molecular weights of these purified proteases were estimated to be 56 X 10(3), 60 X 10(3), and 73 X 10(3) (hereafter designated 56K, 60K, and 73K proteases, respectively). The 73K protease was separated into 73Ka and 73Kb upon isoelectricfocusing. The isoelectric points of the 56K (major) and 60K, 73Ka, and 73Kb proteases (minors) were approximately 5.3, 4.4, 5.8, and 7.3, respectively. Both 56K and 60K enzymes were completely inactivated by EDTA at pH 5.0 and were reactivated by zinc ion; thus, they are metalloenzymes, whereas 73K (73Ka and 73Kb) enzymes appear to be thiol proteases. Carbohydrate, cysteine, and cystine were not detected in the 56K and 60K proteases. Amino acid compositions, partial amino acid sequence, and enzymological and immunological properties revealed that these four enzymes are distinct from each other.

Chromatography, DEAE-Cellulose↗
PubMed1984

Familial amyloidotic polyneuropathy: ocular manifestations with clinicopathological observation.

Clinical findings of ocular involvement in two patients with familial amyloidotic polyneuropathy are described. Both cases revealed irregular pupillary margin, white membranous material on the pupillary border and on the lens surface. Open-angle glaucoma was found in one case, and ocular hypertension in the other. Histopathological examination of the tissues obtained during trabeculectomy in Case 1 revealed a large amount of amyloid substance around the vessels of the conjunctiva and the iris and in the endothelial meshwork of the chamber angle. Electron microscopic observation revealed that amyloid fibrils had formed in the basement membrane of the endothelial cells of the blood vessels in the conjunctiva and the iris. However, no amyloid fibrils were observed in the endothelial cells of the trabecular meshwork. Crossed immunoelectrophoresis of the aqueous humor of Case 1 showed a high-protein content, especially of alpha 1-lipoprotein and ceruloplasmin. The findings described above suggest that glaucoma or ocular hypertension in association with familial amyloidotic polyneuropathy is a result of the accumulation of amyloid substance in the endothelial meshwork.

Adult↗
PubMed1984

Quantitative determination of human aqueous proteins by crossed immunoelectrophoresis.

Crossed immunoelectrophoresis having high resolving power and sensitivity was applied to the human aqueous humor, in an attempt to determine which of the following is the most appropriate parameter for detecting the concentration of protein components: 1) the height of the precipitation line, 2) the length of the line itself or 3) the area under the precipitation line. Furthermore, the concentrations of several proteins were determined in the aqueous humor from normal subjects. Although it has been reported that the area under the precipitation line was proportional to the concentration of the protein, the present study showed that both the height and the length of the precipitation line are also equally valid for concentration determinations. The amount of protein antigens in 100 ml of the normal human aqueous humor were prealbumin 0.31-0.41 mg, albumin 5.4-6.5 mg, alpha 1-acid glycoprotein 0.05-0.17 mg and transferrin 1.3-1.7 mg.

Adult↗
PubMed1983

Studies of human tear proteins--2. Analysis by crossed immunoelectrophoresis of tears from diseased eyes.

By filter paper strips, tears were collected from patients with diseases in the anterior ocular segment and analysed by crossed immunoelectrophoresis. Their crossed immunoelectrophoretic patterns were compared with those of normal subjects. Tear proteins from Sjögren's syndrome. Mikulicz's disease and tumor of the lacrimal gland showed abnormal patterns by crossed immunoelectrophoresis. Tears were collected from patients with lacrimal gland tumor after resection of the tumors. Ten tear-specific proteins were more decreased in these patients than in normal subjects. Serum proteins in the tears of these patients were increased, but secretory IgA (s-IgA) showed no change. A patient with symblepharon showed a marked decrease of both tear-specific proteins and s-IgA. Tears from patients wit epidemic keratoconjunctivitis (EKC), vernal conjunctivitis, herpes simplex keratitis (HSK) and adult inclusion conjunctivitis were analyzed. No remarkable change in tear-specific proteins could be noticed between tears from a case with an early stage of EKC or slight inflammation of the conjunctivitis and tears from the fellow unaffected eye. However, an increase was noted in serum proteins of the diseased eye. The tears collected from a case with severe EKC showed a decrease of tear-specific proteins, but an increase of serum proteins; especially s-IgA showed a significant increase. Tears from patients with EKC, HSK, vernal conjunctivitis and adult inclusion conjunctivitis showed differences in the immunoelectrophoretic patterns of tear proteins according to the severity and duration of the inflammation, as well as the amount of tears secreted. After due consideration of the analysis of tear proteins from some diseases of the anterior ocular segment, the following secretory sites of tear proteins under normal conditions were projected. The 10 tear-specific proteins reported in the previous paper are thought to be largely secreted from the main lacrimal gland. s-IgA is mainly secreted through the excretory ducts of the main lacrimal gland. Serum proteins in the tears are thought to come through the conjunctiva.

Adolescent↗
PubMed1982

Studies of human tear proteins--1. Analysis of tears from normal subjects by crossed immunoelectrophoresis.

Tears were collected from 10 normal subjects by two methods, 1) micropipetting after stimulation with an onion slice, and 2) Schirmer 1 test using a filter paper strip. The tears in the 5 x 5 mm part of the filter paper placed within the conjunctival sac were extracted with a 0.9% NaCl solution. The tear samples so obtained were analyzed by crossed immunoelectrophoresis. Nineteen proteins were identified by the use of monospecific antisera. Ten tear-specific proteins including the specific tear prealbumin of Bonavida et al., lactoferrin and lysozyme were identified by the intermediate gel method. Some differences were found in the pattern of the tear-specific proteins between the tears collected by the two methods, but the pattern was basically similar. Some individual differences were also found. The levels of serum proteins including albumin and IgG varied considerably, but it was thought to be due to dilution by reflex lacrimation during tear sampling. On the other hand, the pattern of the tear-specific proteins was fairly constant. The filter paper method allowed tear protein analysis, even in patients with 0 mm wetting by the Schirmer 1 test. A study of the length-volume relationship of the filter paper wetting showed that the tears contained in the 5 x 5 mm portion of the filter paper were about 1.8 microliters. The filter paper method was thought to offer a reliable clinical tool for the study of the tear proteins in various pathological conditions of the lacrimal secretion.

Adult↗
PubMed1981

Grating test of contrast sensitivity in patients with Minamata disease.

Thirty cases of Minamata disease caused by methyl mercury poisoning with the lesion mainly at the occipital cortex were selected and their spatial contrast sensitivity of vision was examined by the Arden grating chart. At the same time their visual acuity, visual field, and visual evoked cortical potential (VECP) were also investigated. In all cases the results of the Arden test indicated abnormality. Poor results were obtained at higher frequencies of the gratings. VECP elicited by grating pattern reversal stimulus was undertaken in 12 cases out of the 30. The results revealed abnormality almost equal to that shown by the Arden test. Seven out of the 12 cases showed no VECP response. The other 5, giving a response, showed abnormality: when the size of the grating became smaller at higher frequencies, the VECP paused or was not recorded, whereas at low frequencies it was recorded. This finding was in good agreement or was not recorded, whereas at low frequencies it was recorded. This finding was in good agreement with the results of the Arden test. Visual acuity and visual field tests were less sensitive in detecting abnormality. The Arden chart is a sensitive clinical tool for patients with lesions at the cerebral cortex. Furthermore, the test can be used for screening patients who may have come in contrast with organic mercury.

Adult↗